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Sur d’autres sites (10394)
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Fragmented MP4 not playing in ffplay/QuickTime/Safari, but in VLC
6 août 2020, par Stack64I encoded a fMP4-Video (HEVC) in Swift using VideoToolbox and CoreMedia. The resulting fragmented MP4 is only playing in VLC.


The library I am using to write the fMP4 is an HEVC-adapted version of this GitHub-Project : https://github.com/krad/morsel


Process of encoding and writing :


- 

- VideoToolbox : Encoding
SampleBuffer
from the camera (VTCompressionSession
, as described in WWDC 2014 Session 513) - Using
CoreMedia
-Functions (e.g.CMVideoFormatDescriptionGetHEVCParameterSetAtIndex
,CMVideoFormatDescriptionGetDimensions
) to get the encoded streams metadata. I am writing the content ofCMFormatDescriptionGetExtension(description, extensionKey: "SampleDescriptionExtensionAtoms" as CFString)["hvcC"]
directly to the hvcC box. This box is obviously written correctly, when I alter one bit of the box of the mp4, QuickTime throws an error. - I am appending the sample buffer data to the morsel-library, which manages fragmentation and creates the moof and mdat atoms.








The result file is playable in VLC, when I just let the playback "run" without doing anything. When I scroll the time in VLC, VLC crashes and the playback stops.


It is also sort of "playable" in Safari and QuickTime (no error message shown, the playback window opens and the correct length of the file is shown, I can even change to playback time / play/pause, but there is no video shown. The window remains empty. And that is the problem I have. I need to get an fMP4 running in Safari and QuickTime.


The file is not playing at all in ffplay (same problem when converting with ffmpeg). The line where the playback time is shown remains
nan M-V: nan fd= 0 aq= 0KB vq= 0KB sq= 0B f=0/0
, there are no error messages. The playback just does not start.
When playing the file with ffplay, this is the output :

ffplay version 4.3 Copyright (c) 2003-2020 the FFmpeg developers
 built with Apple clang version 11.0.3 (clang-1103.0.32.62)
 configuration: --prefix=/usr/local/Cellar/ffmpeg/4.3_2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
 libavutil 56. 51.100 / 56. 51.100
 libavcodec 58. 91.100 / 58. 91.100
 libavformat 58. 45.100 / 58. 45.100
 libavdevice 58. 10.100 / 58. 10.100
 libavfilter 7. 85.100 / 7. 85.100
 libavresample 4. 0. 0 / 4. 0. 0
 libswscale 5. 7.100 / 5. 7.100
 libswresample 3. 7.100 / 3. 7.100
 libpostproc 55. 7.100 / 55. 7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
 Metadata:
 major_brand : mp42
 minor_version : 1
 compatible_brands: mp41mp42isomhlsf
 creation_time : 2020-08-03T20:41:08.000000Z
 Duration: N/A, bitrate: N/A
 Stream #0:0(und): Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv), 1920x1080, SAR 1:1 DAR 16:9, 1000000000.00 tbr, 1000000000.00 tbn, 1000000000.00 tbc (default)
 Metadata:
 creation_time : 2020-08-03T20:41:08.000000Z
 handler_name : video
 nan M-V: nan fd= 0 aq= 0KB vq= 0KB sq= 0B f=0/0 



My file has this structure :


ftyp
moov
 mvhd
 trak
 tkhd
 mdia
 mdhd
 hdlr
 minf
 vmhd
 dinf
 dref
 stbl
 stsd
 stts
 stsc
 stsz
 stco
 mvex
 trex
moof-(1)
mdat
moof-(2)
mdat 
...



The result file I want to create should be like the fMP4 served within this HLS playlist : (Example : https://developer.apple.com/streaming/examples/advanced-stream-hevc.html, Playlist : https://devstreaming-cdn.apple.com/videos/streaming/examples/bipbop_adv_example_hevc/master.m3u8)
This file has the following structure :


ftyp
moov
 mvhd
 trak
 tkhd
 mdia
 mdhd
 hdlr
 minf
 vmhd
 dinf
 dref
 stbl
 stsd
 stts
 stsc
 stsz
 stco
 trak (same structure as above)
 mvex
 trex
moof-(1)
mdat
moof-(2)
mdat 
...



This file from Apple plays perfectly in ffmpeg and QuickTime/Safari. Except for the second
trak
atom, it has the same structure.

The "good" file is : https://devstreaming-cdn.apple.com/videos/streaming/examples/bipbop_adv_example_hevc/v14/main.mp4 (It is intended for use in a HLS Playlist I've downloaded it with curl)


The "bad" file is : https://www.transfernow.net/ddl/fmp4_bad (link should work, tested it just now :) ). The video shows a slowly rotating sheet of paper.


Any suggestions what the problem with my file is ?
Thanks in advance !


- VideoToolbox : Encoding
-
Prevent ffmpeg from changing the intensity of colors while downscaling the resolution of the video
29 août 2022, par dravitI have a use case where I need to downscale a
716x1280
mp4 video to358x640
(half of the original). Command that I used is

ffmpeg -i ./input.mp4 -vf "scale=640:640:force_original_aspect_ratio=decrease,pad=ceil(iw/2)*2:ceil(ih/2)*2" ./output.mp4



Out of 10 sample videos, 2 of the them suffered impact on colors. Below I have attached a comparison from the one which was impacted the most.




NOTE : The one on the right is a frame from the original video and the frame on the left is the one from the processed (down scaled) video. Notice the colors red and green in the image (even the skin color and hair color were changed).


What I am looking for is


- 

- Is there any way I can prevent changes like these happening ? Probably some flag on saturation, brightness, contrast or any other parameter.
- I am assuming that ffmpeg uses some default settings while downscaling a video. What made ffmpeg change colors only for these two videos ? If it made similar changes for the rest of the videos as well, how to predict this behaviour before hand ?






EDIT :


What I already have Tried ?


- 

-crf
with values 0 and 18.-preset veryslow
as mentioned here






None helped


Mediainfo input V/S output







 param 

input 

output 







 color range 

Limited 

NA (attribute not in description) 




 color primaries 

BT.2020 

NA (attribute not in description) 




 transfer characteristics 

HLG 

NA (attribute not in description) 




 matrix coefficients 

BT.2020 non-constant 

NA (attribute not in description) 




 bit deapth 

8 

8 









Logs of the ffmpeg command


ffmpeg -i ./input.mp4 -vf "scale=640:640:force_original_aspect_ratio=decrease,pad=ceil(iw/2)*2:ceil(ih/2)*2" -movflags +faststart ./output.mp4
ffmpeg version 4.3.1 Copyright (c) 2000-2020 the FFmpeg developers
 built with Apple clang version 12.0.0 (clang-1200.0.32.28)
 configuration: --prefix=/usr/local/Cellar/ffmpeg/4.3.1_9 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack
 libavutil 56. 51.100 / 56. 51.100
 libavcodec 58. 91.100 / 58. 91.100
 libavformat 58. 45.100 / 58. 45.100
 libavdevice 58. 10.100 / 58. 10.100
 libavfilter 7. 85.100 / 7. 85.100
 libavresample 4. 0. 0 / 4. 0. 0
 libswscale 5. 7.100 / 5. 7.100
 libswresample 3. 7.100 / 3. 7.100
 libpostproc 55. 7.100 / 55. 7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from './input.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.45.100
 Duration: 00:00:30.05, start: 0.000000, bitrate: 10366 kb/s
 Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt2020nc/bt2020/arib-std-b67), 716x1280, 10116 kb/s, 30 fps, 30 tbr, 19200 tbn, 38400 tbc (default)
 Metadata:
 handler_name : Core Media Video
 Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 245 kb/s (default)
 Metadata:
 handler_name : Core Media Audio
Stream mapping:
 Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
 Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x7faab4808800] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x7faab4808800] profile High, level 3.0, 4:2:0, 8-bit
[libx264 @ 0x7faab4808800] 264 - core 161 r3027 4121277 - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to './output.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.45.100
 Stream #0:0(und): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 358x640, q=-1--1, 30 fps, 15360 tbn, 30 tbc (default)
 Metadata:
 handler_name : Core Media Video
 encoder : Lavc58.91.100 libx264
 Side data:
 cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
 Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : Core Media Audio
 encoder : Lavc58.91.100 aac
[mp4 @ 0x7faab5808800] Starting second pass: moving the moov atom to the beginning of the file
frame= 901 fps=210 q=-1.0 Lsize= 3438kB time=00:00:30.02 bitrate= 938.0kbits/s speed=7.01x
video:2933kB audio:472kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.974633%
[libx264 @ 0x7faab4808800] frame I:6 Avg QP:22.60 size: 20769
[libx264 @ 0x7faab4808800] frame P:228 Avg QP:24.84 size: 7657
[libx264 @ 0x7faab4808800] frame B:667 Avg QP:27.59 size: 1697
[libx264 @ 0x7faab4808800] consecutive B-frames: 0.9% 0.9% 1.0% 97.2%
[libx264 @ 0x7faab4808800] mb I I16..4: 9.5% 64.6% 26.0%
[libx264 @ 0x7faab4808800] mb P I16..4: 2.5% 12.2% 2.5% P16..4: 37.2% 20.6% 11.2% 0.0% 0.0% skip:13.7%
[libx264 @ 0x7faab4808800] mb B I16..4: 0.4% 2.1% 0.2% B16..8: 42.2% 7.1% 1.2% direct: 1.8% skip:44.9% L0:39.4% L1:52.8% BI: 7.8%
[libx264 @ 0x7faab4808800] 8x8 transform intra:72.2% inter:74.2%
[libx264 @ 0x7faab4808800] coded y,uvDC,uvAC intra: 61.8% 67.2% 20.2% inter: 16.7% 13.9% 1.3%
[libx264 @ 0x7faab4808800] i16 v,h,dc,p: 24% 19% 7% 50%
[libx264 @ 0x7faab4808800] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 21% 16% 15% 6% 9% 11% 7% 10% 6%
[libx264 @ 0x7faab4808800] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 16% 13% 7% 9% 10% 7% 9% 4%
[libx264 @ 0x7faab4808800] i8c dc,h,v,p: 53% 16% 26% 5%
[libx264 @ 0x7faab4808800] Weighted P-Frames: Y:3.9% UV:1.8%
[libx264 @ 0x7faab4808800] ref P L0: 57.8% 19.5% 14.8% 7.8% 0.1%
[libx264 @ 0x7faab4808800] ref B L0: 90.7% 7.2% 2.1%
[libx264 @ 0x7faab4808800] ref B L1: 95.3% 4.7%
[libx264 @ 0x7faab4808800] kb/s:799.80
[aac @ 0x7faab2036a00] Qavg: 189.523



-
how to add hvt1 hvc2 to ffmpeg ?
19 août 2020, par user10716022i only add libavformat library isom.c


{ AV_CODEC_ID_HEVC , MKTAG ('h', 'v', 'c', '2') }, /* HEVC / H.265 coded
with gpac */
 { AV_CODEC_ID_HEVC , MKTAG ('h', 'v', 't', '1') }, /* HEVC / H.265 coded
with gpac */



i want use ffmpeg mpeg dash srd


MPD video code ffmpeg do not have
this is my MPD


<?xml version="1.0"?>

<mpd xmlns="urn:mpeg:dash:schema:mpd:2011" minbuffertime="PT1.500S" type="static" mediapresentationduration="PT0H3M37.792S" maxsegmentduration="PT0H0M5.000S" profiles="urn:mpeg:dash:profile:isoff-live:2011">
 <programinformation moreinformationurl="http://gpac.io">
 
 </programinformation>

 <period duration="PT0H3M37.792S">
 <adaptationset segmentalignment="true" maxwidth="1920" maxheight="1012" maxframerate="24" par="1920:1012" lang="und" startwithsap="1">
 <essentialproperty schemeiduri="urn:mpeg:dash:srd:2014" value="1,0,0,0,0"></essentialproperty>
 <segmenttemplate media="output_qp22_dash_track1_$Number$.m4s" initialization="hight01_set1_init.mp4" timescale="24000" startnumber="1" duration="120000"></segmenttemplate>
 <representation mimetype="video/mp4" codecs="hvc2.1.6.L186.80" width="1920" height="1012" framerate="24" sar="1:1" bandwidth="3010576">
 </representation>
 </adaptationset>
</period>
</mpd>